IDEF ZERO

Node A6 · Acronym decoder

RAM

Reliability, Availability, and Maintainability

What it actually means

The triad of "ility" disciplines: how often it breaks (reliability), how quickly it's restored (maintainability), and the resulting fraction of time it's usable (availability). These are design properties, set by architecture and parts choices early — testing later only measures what the design already decided. In program-controls contexts the same letters mean Responsibility Assignment Matrix.

Where you'll meet it

Specification trees, sustainment metrics, and reliability program plans.

Related terms

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